gdb/linux: Delete all other LWPs immediately on ptrace exec event

[binutils-gdb.git] / gdb / linux-nat.c

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index f73e52f9617ea475b202d96cc0d522e36d2e03bb..97d80053c6f639ea3548fd7f4e761dedbc4abfec 100644 (file)
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -2001,6 +2001,21 @@ linux_handle_extended_wait (struct lwp_info *lp, int status)
         thread execs, it changes its tid to the tgid, and the old
         tgid thread might have not been resumed.  */
       lp->resumed = 1;
+
+      /* All other LWPs are gone now.  We'll have received a thread
+        exit notification for all threads other the execing one.
+        That one, if it wasn't the leader, just silently changes its
+        tid to the tgid, and the previous leader vanishes.  Since
+        Linux 3.0, the former thread ID can be retrieved with
+        PTRACE_GETEVENTMSG, but since we support older kernels, don't
+        bother with it, and just walk the LWP list.  Even with
+        PTRACE_GETEVENTMSG, we'd still need to lookup the
+        corresponding LWP object, and it would be an extra ptrace
+        syscall, so this way may even be more efficient.  */
+      for (lwp_info *other_lp : all_lwps_safe ())
+       if (other_lp != lp && other_lp->ptid.pid () == lp->ptid.pid ())
+         exit_lwp (other_lp);
+
       return 0;
     }